Potential role of gut microbiota in patients with COVID-19, its relationship with lung axis, central nervous system (CNS) axis, and improvement with probiotic therapy

Abstract

Coronavirus Disease 2019 (COVID-19) is a pandemic disease caused by a new corona virus. COVID-19 affects different people in different ways. COVID-19 could affect the gastrointestinal system via gut microbiota impairment. Gut microbiota could affect lung health through a relationship between gut and lung microbiota, which is named gut-lung axis. Gut microbi- ota impairment plays a role in pathogenesis of various pulmonary disease states, so GI diseases were found to be associated with respiratory diseases. Moreover, most infected people will develop mild to moderate gastrointestinal (GI) symptoms such as diarrhea, vomiting, and stomachache, which is caused by impairment in gut microbiota. Therefore, the current study aimed to review potential role of gut microbiota in patients with COVID-19, its relation with lung axis, Central Nervous System (CNS) axis and improvement with probiotic therapy. Also, this review can be a guide for potential role of gut microbiota in patients with COVID-19.

Celiac Disease and Targeting the Molecular Mechanisms of Autoimmunity in COVID Pandemic

“…Recent publications have suggested that disruption of the microbiota and impairments in intestinal barrier function triggers local inflammation by activating the immune system and causing severe COVID-19 infections on the gut–lung–brain axis in adults [ 154 , 155 ] and likely in children diagnosed with MIS-C. GI dysfunction in MIS-C is under ongoing investigation [ 156 , 157 ].…”

“…The differences between children and adults in connection with the previously mentioned gastrointestinal implications of COVID-19 are depicted in Figure 1. [154,155] and likely in children diagnosed with MIS-C. GI dysfunction in MIS-C is under ongoing investigation [156,157].…”

ACE-2 receptor-associated COVID-19 lesions and sequelae

“…5,6,9 In the gastrointestinal tract, the gut-lung axis has been described as responsible for damage to the intestinal mucosa, possibly conferring an increased risk of inflammatory bowel disease and chronic liver disease, as well as increased injury at the pulmonary level due to modification of the immune response by producing an unhealthy gut microbiome. [20][21][22] The probable destruction of the β-cells of the islets of Langerhans in the pancreas may trigger insulin-dependent diabetes mellitus and further increase morbidity and mortality in patients. 6,23,24 In the central nervous system, systemic inflammation and entry of the virus through ACE-2 receptors expressed in the brain are probably responsible for a decrease in cognitive capacity, memory loss, fatigue, and neurogenic hypertension.…”

“…Experimental studies have shown that the absence of a healthy intestinal microbiome generates consequences in the preservation of the immune system, avoiding exaggerated or deficient responses to pathogens that can be harmful to other organs such as the lungs (gut-lung axis). [20][21][22] Páncreas -Islets of Langerhans. ACE-2 expression has been shown to be higher in islets of Langerhans (site of insulin production) and lower in exocrine cells.…”